Expression of BMP‐2 and TGF‐β1 mRNA during healing of the rabbit mandible

Abstract

To identify the cell types which produce BMP and TGF-beta during fracture healing and to elucidate the interactions between BMP and TGF-beta in regulating cell proliferation and differentiation at various stages, an experimental model of fracture healing in the rabbit mandible was established and the expression of BMP-2 and TGF-beta 1 mRNA was studied at different healing stages by in situ hybridization. The results showed that undifferentiated mesenchymal cells, differentiating osteoblasts and chondroblasts, had higher levels of BMP-2 mRNA at the stage of intramembranous bone formation and early chondrogenesis, while the level of TGF-beta 1 mRNA was higher in chondrocytes and active differentiated osteoblasts during chondrogenesis and endochondral ossification, respectively. We conclude that BMP-2 expression was correlated with the differentiation of mesenchymal cells into osteoblasts and chondrocytes. TGF-beta 1 mRNA expression was closely associated with the active synthetic stage of osteoblasts and chondrocytes. These observations suggest that both BMP and TGF-beta are involved in the regulation of fracture healing. BMP may play an important role in bone induction and early chondrogenesis, while TGF-beta regulates the proliferation and active synthetic ability of chondrocytes and osteoblasts.

Pro-inflammatory Cytokine Tumor Necrosis Factor-α Induces Bone Morphogenetic Protein-2 in Chondrocytes via mRNA Stabilization and Transcriptional Up-regulation

“…The growth factor is expressed in the process of bone healing where it regulates cellular differentiation, proliferation, and matrix production (7,8). Various tumors have been found to express BMP-2.…”

Non-viral gene therapy for bone tissue engineering

“…This could be caused by a better cell functionality due to better nutrient supply and waste removal due to shorter diffusion distances. The low background levels of BMP-2 protein produced in the control group is normal and reported before 240 . Figure 4.…”

The role of growth factors in extraction wound healing

“…Najizraženije dejstvo im je diferencijacija mezenhimalnih ćelija u osteoblaste i hondroblaste 23,24 . Neke studije 24 ukazuju na to da BMP ne stimulišu zrele osteoblaste, a zreli fibroblasti nisu sposobni da indukuju osteogenu aktivnost posle tretmana BMP-2. Ovo bi značilo da je osteogeni uticaj BMP usmeren isključivo na nezrele i multipotentne ćelije.…”

“…They have the strongest effect on differentiation of mesenchymal cells into osteoblasts and hondroblasts 23,24 . Some studies 24 suggest that BMPs do not stimulate mature osteoblasts and that mature fibroblasts are unable to induce osteogenic activity after BMPtreatment. This would mean that BMPs have an osteogenic effect exclusively on immature and multi-potent cells.…”